<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

欢迎用户 {{ username }} 登录

<br>
{{ 1+2 }}
<br>
{{ time.time() }}
<br>
{{ haha() }}
<br>

{% if username!='no' %}
    欢迎用户 {{ username }} 登录
{% else %}
    您还没有登录
{% end %}
<br>
{% for i in li%}
    {{ i }} <br>
{% end %}

</body>
</html>